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Chemosensory Perception of Predators by Larval Amphibians Depends on Water Quality.

Troyer RR, Turner AM - PLoS ONE (2015)

Bottom Line: Tadpoles housed in tap water responded to predator cues with an activity reduction of 49%.Tadpoles housed in stream water and wastewater effluent responded to predator cues by reducing activity by 29% and 24% respectively.These results show that alteration of the chemical environment can mediate chemical perception of predators in aquatic ecosystems.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Clarion University, Clarion, PA, United States of America.

ABSTRACT
The acquisition of sensory information by animals is central to species interactions. In aquatic environments, most taxa use chemical cues to assess predation risk and other key ecological factors. A number of laboratory studies suggest that anthropogenic pollutants can disrupt chemoreception, even when at low, non-toxic concentrations, but there are few tests of whether real-world variation in water quality affects chemoreception. Here we investigate whether chemosensory perception of predators by the gray treefrog, Hyla versicolor, depends on water quality. We evaluated the anti-predator response of anuran tadpoles housed in water collected from three sites that represent strong contrasts in the concentration and types of dissolved solids: de-chlorinated tap water, water from an impaired stream, and treated wastewater effluent. Behavioral assays were conducted in laboratory aquaria. Chemical cues associated with predation were generated by feeding tadpoles to dragonfly predators held in containers, and then transferring aliquots of water from dragonfly containers to experimental aquaria. Tadpoles housed in tap water responded to predator cues with an activity reduction of 49%. Tadpoles housed in stream water and wastewater effluent responded to predator cues by reducing activity by 29% and 24% respectively. The results of factorial ANOVA support the hypothesis that the response to predator cues depended on water type. These results show that alteration of the chemical environment can mediate chemical perception of predators in aquatic ecosystems. Because most aquatic species rely on chemoreception to gather information on the location of food and predators, any impairment of sensory perception likely has important ecological consequences.

No MeSH data available.


Effect of predator cues on activity of gray treefrog tadpoles.Tadpoles were housed in water drawn from three sources. Activity was scored as mean proportion of individuals that moved during 20-second observation bouts. Response to predator cues depended on water source. Bars represent one standard error, N = 16 replicates per treatment combination.
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pone.0131516.g001: Effect of predator cues on activity of gray treefrog tadpoles.Tadpoles were housed in water drawn from three sources. Activity was scored as mean proportion of individuals that moved during 20-second observation bouts. Response to predator cues depended on water source. Bars represent one standard error, N = 16 replicates per treatment combination.

Mentions: Dragonfly cues had a large effect on tadpole activity, as mean activity was reduced from 33% in the absence of predator cues to 21% in the presence of predator cues, a highly significant depression (Table 2). However, the effect of predator cues on tadpole activity depended on water treatment (Fig 1). Predator cues induced a 49% reduction in activity for tadpoles in tap water, a 29% reduction for tadpoles in river water, and a 24% reduction for tadpoles in wastewater effluent, yielding a significant interaction between the effects of predator cues and water type (Table 2). One-way ANOVA’s testing predator effects within each water type reveal that cues had highly significant effects on tadpoles housed in tap water (F1,30 = 17.3, P < 0.001), but predator cues had at best marginally significant effects on tadpoles housed in river water (F1,30 = 3.78, P = 0.06) and wastewater effluent (F1,30 = 4.20, P = 0.05).


Chemosensory Perception of Predators by Larval Amphibians Depends on Water Quality.

Troyer RR, Turner AM - PLoS ONE (2015)

Effect of predator cues on activity of gray treefrog tadpoles.Tadpoles were housed in water drawn from three sources. Activity was scored as mean proportion of individuals that moved during 20-second observation bouts. Response to predator cues depended on water source. Bars represent one standard error, N = 16 replicates per treatment combination.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482611&req=5

pone.0131516.g001: Effect of predator cues on activity of gray treefrog tadpoles.Tadpoles were housed in water drawn from three sources. Activity was scored as mean proportion of individuals that moved during 20-second observation bouts. Response to predator cues depended on water source. Bars represent one standard error, N = 16 replicates per treatment combination.
Mentions: Dragonfly cues had a large effect on tadpole activity, as mean activity was reduced from 33% in the absence of predator cues to 21% in the presence of predator cues, a highly significant depression (Table 2). However, the effect of predator cues on tadpole activity depended on water treatment (Fig 1). Predator cues induced a 49% reduction in activity for tadpoles in tap water, a 29% reduction for tadpoles in river water, and a 24% reduction for tadpoles in wastewater effluent, yielding a significant interaction between the effects of predator cues and water type (Table 2). One-way ANOVA’s testing predator effects within each water type reveal that cues had highly significant effects on tadpoles housed in tap water (F1,30 = 17.3, P < 0.001), but predator cues had at best marginally significant effects on tadpoles housed in river water (F1,30 = 3.78, P = 0.06) and wastewater effluent (F1,30 = 4.20, P = 0.05).

Bottom Line: Tadpoles housed in tap water responded to predator cues with an activity reduction of 49%.Tadpoles housed in stream water and wastewater effluent responded to predator cues by reducing activity by 29% and 24% respectively.These results show that alteration of the chemical environment can mediate chemical perception of predators in aquatic ecosystems.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Clarion University, Clarion, PA, United States of America.

ABSTRACT
The acquisition of sensory information by animals is central to species interactions. In aquatic environments, most taxa use chemical cues to assess predation risk and other key ecological factors. A number of laboratory studies suggest that anthropogenic pollutants can disrupt chemoreception, even when at low, non-toxic concentrations, but there are few tests of whether real-world variation in water quality affects chemoreception. Here we investigate whether chemosensory perception of predators by the gray treefrog, Hyla versicolor, depends on water quality. We evaluated the anti-predator response of anuran tadpoles housed in water collected from three sites that represent strong contrasts in the concentration and types of dissolved solids: de-chlorinated tap water, water from an impaired stream, and treated wastewater effluent. Behavioral assays were conducted in laboratory aquaria. Chemical cues associated with predation were generated by feeding tadpoles to dragonfly predators held in containers, and then transferring aliquots of water from dragonfly containers to experimental aquaria. Tadpoles housed in tap water responded to predator cues with an activity reduction of 49%. Tadpoles housed in stream water and wastewater effluent responded to predator cues by reducing activity by 29% and 24% respectively. The results of factorial ANOVA support the hypothesis that the response to predator cues depended on water type. These results show that alteration of the chemical environment can mediate chemical perception of predators in aquatic ecosystems. Because most aquatic species rely on chemoreception to gather information on the location of food and predators, any impairment of sensory perception likely has important ecological consequences.

No MeSH data available.